1 Principles topenlarge
Triangle of stability
Stability of the distal humerus is based on 3 columns: Medial, lateral, and the articular surface.
In complete articular fractures, all 3 columns have to be restored.
2 Identification of the bony fragments topenlarge
Take your time to identify all bony fragments, and compare them to the x-rays.
Mobilize the fragment
Some displaced fragments are not immediately seen after osteotomy. Be sure
to account for all fragments. Mobilize the fragments and bring them into the
Clean out the fracture by removing blood clots, loose pieces of bone, and interposed tissue. Inspect the joint to ensure that no intraarticular fracture component was missed when examining the imaging.
3 Reconstruction of the articular surface topenlarge
Reduce and hold the articular fragments using cannulated screw guide wires.
Assemble all small fragments covered by cartilage, even if they have no soft tissue connection. A headless screw is often a good choice for fixing some of these fragments.
Definitive fixation of articular fragments
Insert a cannulated screw over the guide wire after pre-drilling the pilot hole. Alternatively, insert a non-cannulated screw in the standard manner parallel to the wire, and then remove the wire.
Insert the screw from the lateral to the medial side, so that the screw head does not irritate the ulnar nerve and conflict with the planned position of the medial plate.
If possible, insert a second screw to improve rotational stability.
Bone stock quality
Use the lag screw technique only in good bone quality and when anatomical reconstruction of all articular fragments is possible.
In osteoporotic bone, or when bone graft has to be added to fill an articular gap, use a position screw to avoid deformation of the articular surface.
In inferior bone quality, or when a fragment is missing, use of a lag screw, producing interfragmentary compression, will deform the articular surface.
In case of missing bone, always use bone graft or fill the defect with the remaining small fragments.
4 Condylar reattachment topenlarge
Reduce the reconstituted articular mass to the metaphysis and use K-wires for preliminary fixation.
The plates must be carefully contoured using an appropriate malleable template.
Pace the lateral column plate dorsally and the medial column plate medially. In this position their planes form an angle of approximately 90 degrees to each other.
First place a 3.5 mm reconstruction plate posterolaterally. It may curve around the capitellum which has no cartilage cover posteriorly.
The comminution is bridged if it cannot be precisely reduced and fixed with absolute stability. A slightly longer plate is used to provide additional stability.
In a more distal fracture, the reconstruction plate may be contoured to extend all the way to the edge of the capitellar articular surface. It will not interfere with the radial head during the extension of the joint. The more bone is covered by the plate, the greater is the stability achieved.
Placement of the lateral plate
Insert a K-wire through the distal hole. As the plate is pulled proximally,
stable contact with the bone is obtained.
Now insert the proximal screw.
Insert the remaining screws.
Place another plate medially on the crest of the medial supracondylar ridge, its plane at right angles to the lateral plate to increase stability.
It is recommended to insert the distal screw into the trochlea below the medial epicondyle.